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What Octane Does Manual for 5.0 Call For?

  • Thread starter Thread starter rseifert
  • Start date Start date May 29, 2004
R

rseifert

Founding Member
Mar 13, 2001
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Lung Gyland, NY
May 29, 2004
#1
  • May 29, 2004
  • #1
Gas prices suck now, especially on rip off long island where i live. I always got 93 for my car even though the engine is completely stock besides having headers. I never changed the timing or anything like that either. Can I run 87, or will i get knocking? If it is the least bad for my car I wont run 87, however at this point, if im buying 93 for nothing im sure as hell gonna stop. Thanks.
 
9

90stangLX302

New Member
Dec 2, 2003
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Good ol' Bellaire Ohio
May 29, 2004
#2
  • May 29, 2004
  • #2
87 will be fine with the mod you listed, i can run 87 in mine with no problems and i am runnin 16* btdc timing. Help save a few bucks at the pump since I am there every other day
 

Michael Yount

Mustang Master
Apr 10, 2002
9,039
6
79
Charlotte, NC
May 29, 2004
#3
  • May 29, 2004
  • #3
Yup - in fact, you may notice a slight increase in gas mileage running 87 octane; the lower the octane, the easier it is to ignite and it burns slightly quicker. I've dropped mine back from 93 to 87 (I've got a mild heads/cam/intake/exhaust combo) with no detonation at all and it appears (2 tanks checked) I've picked up about 1 mpg on city and hwy.
 

axeman

Founding Member
Feb 9, 2001
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Elizabethtown, PA
May 29, 2004
#4
  • May 29, 2004
  • #4
i run 87. i have since last summer when the gas prices went up a little. if you go to the track, you may even notice a little bump in performance since you are running 93 without advancing your timing.

i checked my gas milage the other day, even though it was almost all highway miles, i got 23.7mpg with 4.30 gears.
 

YardSpecial

New Member
Mar 20, 2003
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MT
May 29, 2004
#5
  • May 29, 2004
  • #5
What they all said, 87 is the FACTORY recommend fuel grade
 
I

iwashmycar

20+ Year Stangneter
Apr 7, 2004
1,236
1
39
Columbus, Ohio
May 29, 2004
#6
  • May 29, 2004
  • #6
87 all the way. I usually get 300 miles to the tank here.
 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
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Northern KY
May 29, 2004
#7
  • May 29, 2004
  • #7
My god, i dont know what my timing is because i dont have a light, but if i run anything less than 93 i get the pinger.
 

YardSpecial

New Member
Mar 20, 2003
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MT
May 29, 2004
#8
  • May 29, 2004
  • #8
Um, just retard the timing till the ping goes away...........

Chevy SB trick for years, tune to the gas octane.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,235
17,920
224
Massachusetts
May 29, 2004
#9
  • May 29, 2004
  • #9
Yup, ever since gas prices went way up, i backed timing down to 10 degrees so i could run 87 again
 

admstng

New Member
Dec 12, 2003
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May 29, 2004
#10
  • May 29, 2004
  • #10
where are you on long island? i'm in holbrook in suffolk county
 
R

rseifert

Founding Member
Mar 13, 2001
200
0
0
Lung Gyland, NY
May 29, 2004
#11
  • May 29, 2004
  • #11
Thanks for the replies guys. I will not waste my money anymore spending 20 cents more a gallon for 93. i live in Islip
 

TRWXXA

Member
Jan 18, 2003
190
1
19
RIGHT BEHIND YOU!!!... Made you look.
May 29, 2004
#12
  • May 29, 2004
  • #12
85_SS_302_Coupe said:
My god, i dont know what my timing is because i dont have a light, but if i run anything less than 93 i get the pinger.
Click to expand...

Your timing is not the only thing that could cause pinging.

You may have carbon buildup in the cylinders. This buildup can artificially increase your compression ratio.

Small carbon deposits in the cylinder can also cause it. The deposits heat up red hot, where they can ignite the fuel/air mixture prematurely.

Check the timing. If it's ok, you might want to try some kind of engine cleaner.
 
8

87'GTstang

New Member
Feb 16, 2004
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0
May 29, 2004
#13
  • May 29, 2004
  • #13
True. The best I have gotten away with is 12 degrees with a "healthy" engine. 14 is about as high as i'de go with stock form. Basically though it's just trial and error. Keep backing your timing down unil the pinging ceases. But, if you have to go below 10 degrees timing, than you've got an issue that needs attention seriously. Oh yeah, 87 is what most every non-overhead cammed engine comes built to run on.
 

FiveO

Founding Member
Jan 28, 2001
1,146
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0
NJ
May 29, 2004
#14
  • May 29, 2004
  • #14
i run 89 on 16* timing.... i could probably run 87 on her, but i noticed i get horrible gas mileage on 87. and i can get about 15-20 more miles on 93....89 being in the middle.... its kinda odd. then again getting 180 miles to a tank on a stock motor isn't great....
 

siege

New Member
Feb 23, 2003
651
0
0
Peoria, AZ
May 30, 2004
#15
  • May 30, 2004
  • #15
iwashmycar said:
87 all the way. I usually get 300 miles to the tank here.
Click to expand...

300? are you serious? man, I only get about 180, that sucks.
I, too, recently bumped the timing back to 10 and switched to 87 from 91 (we don't have 93 here)...got tired of spending $35 to fill the tank
 
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